JP2001077651A - Piezoelectric device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piezoelectric device with improved impact resistance by securing adhering strength between a piezoelectric vibrator and a conductive adhesive member, which is superior in electrical characteristics by preventing a basic wave from damping and has the piezoelectric vibrator which can be fixed in cantilever. SOLUTION: In a piezoelectric device 1, a piezoelectric vibrator 3 forming an exiting electrodes 31, 33 on both of the main surfaces of a rectangular piezoelectric substrate 30 and leading electrodes 32, 34 on the lower surface on one short edge side of the substrate 30 and an insulated substrate 21 forming electrode pads 22, 23 having bumps on the surface are connected by a conductive adhesive member 4, arranged on the lower surface and the end face on the short edge side of the vibrator 3. At setting the width of the member 4 to W1, the width of the short edge direction of the piezoelectric element to be W and the length of a long edge direction to be L, they are expressed in the relation 0.22 W<=W1<0.5 W, L<=2.3 W.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a quartz oscillator in which a piezoelectric vibrating element is joined to an insulating substrate via a conductive adhesive member.
The present invention relates to a piezoelectric device such as a crystal oscillator and a piezoelectric oscillator.

[0002]

2. Description of the Related Art A conventional piezoelectric vibrator which is a crystal vibrator will be described with reference to a top view of FIG. 8 and a sectional view of FIG.

A piezoelectric vibrator 51 having a piezoelectric vibrating element mounted on an insulating substrate such as a ceramic package is disclosed in Japanese Patent Laid-Open No. 7-2406.
53 and the like, as shown in FIGS.

The ceramic package 52 is formed by laminating ceramic insulating plates of alumina or the like, and a cavity having a step portion 55 for fixing a piezoelectric vibrator is formed inside the ceramic package 52. Grooves 5 are provided at both ends in the width direction of the stepped portion 55 for fixing the piezoelectric vibrator.
8 are formed.

[0005] The piezoelectric vibrating element 53 is provided by using the stepped portion 55 for fixing and the stepped portion 56 on the front end side of the ceramic package 52.
Is placed. Here, after applying a conductive paste to the fixing stepped portion 55 side, the piezoelectric vibrating element 53 is mounted, the conductive paste is cured, and the conductive paste is bonded and fixed via the conductive adhesive member 57. The opening of the cavity of the ceramic package 52 is hermetically sealed by a metal lid 59.

Further, since grooves 58 are formed at both ends in the width direction of fixing stepped portion 55 and ceramic package 52, when a large amount of conductive resin paste supplied to fixing stepped portion 55 is applied. Excess paste flows into the groove 58, and the conductive resin paste between the fixing stepped portion 55 and the piezoelectric vibration element 53 is made uniform. As a result, the variation in the shrinkage stress of the conductive resin paste during the heat curing is reduced, and the variation in the oscillation frequency and the variation in the characteristics are suppressed.

[0007]

However, in the prior art, in order to form the fixing stepped portion 55, the ceramic package 52 has a flat ceramic layer and a fixing stepped portion provided on the ceramic layer. 55 is composed of a ring-shaped ceramic layer having an opening at the center and a ring-shaped ceramic layer having a large opening at the center. Therefore, even if the height of the ceramic package 52 is reduced, there is a limit and it is difficult to reduce the height.

The piezoelectric vibrating element 53 is bonded to the fixing stepped portion 55 on which the electrode pad is formed via a conductive resin paste. When spread in the paste, the fundamental wave vibration was damped and the CI value tended to deteriorate. Conversely, if the amount of paste is reduced, damping of the fundamental wave is suppressed and the CI value is improved, but the mechanical strength of the joint is weakened, and if an external impact is applied due to dropping etc., peeling is likely to occur As a result, the oscillation frequency may greatly change or an oscillation failure may occur.

That is, according to the shape of the piezoelectric vibration element 53,
It is necessary to strictly control the arrangement shape of the conductive resin paste.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to control the arrangement of a conductive resin paste by allowing a piezoelectric vibrating element to be bonded to a flat substrate. And the mechanical strength of the joint becomes weaker,
An object of the present invention is to provide a piezoelectric device capable of effectively suppressing peeling and fluctuation in oscillation frequency when an external impact is applied due to a drop or the like.

[0011]

According to the present invention, an excitation electrode is provided on both main surfaces of a rectangular piezoelectric substrate, and a pair of extraction electrodes connected to the excitation electrode is provided on a lower surface near one short side of the piezoelectric substrate. The formed piezoelectric vibrating element and an insulating substrate on which a pair of electrode pads having bumps on the surface are formed are joined via a conductive adhesive member so that the extraction electrode and the electrode pad are electrically connected to each other. When the width of the conductive adhesive member is W1, the width of the piezoelectric vibrating element in the short side direction is W, and the length in the long side direction is L, 0.22W ≦ W1 <0.5W. A piezoelectric device represented by the following relationship: L ≦ 2.3W.

[0012]

According to the present invention, an electrode pad having a bump is formed on an insulating substrate having a flat surface, and this electrode pad and one short side end of the piezoelectric vibrating element are joined by a conductive adhesive member. I have. That is, the piezoelectric vibrating element can be cantilevered by the flat substrate, and the stepped portion for fixing is not required.

Therefore, the member for fixing the piezoelectric vibration element is simplified, the whole piezoelectric device is simplified, and the height can be reduced.

When the width of the conductive adhesive member at the short side end face of the piezoelectric vibrating element is W1, the width of the piezoelectric vibrating element in the short side direction is W, and the length in the long side direction is L, Since 22W ≦ W1 <0.5W L ≦ 2.3W, the cantilever fixed type piezoelectric vibrating element can be supported with stable bonding strength, and at the same time, fluctuations in oscillation characteristics can be effectively suppressed.

If the width W1 of the conductive adhesive member at the short side end face of the piezoelectric vibrating element is less than 0.22W of the width of the piezoelectric vibrating element in the short side direction, the oscillation frequency after the drop test is less than 0.22W. Fluctuations become extremely worse. On the other hand, if it exceeds 0.5 W, the conductive connection members arranged on the pair of electrode pads will be short-circuited.

When the width of the piezoelectric vibrating element in the short side direction W and the length L in the long side direction deviates from L ≦ 2.3 W, the length L becomes longer than the width W. The conductive bonding member formed by curing the conductive paste disposed on one short side makes it difficult to lift the other short side, and the impact resistance is deteriorated.

[0017]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a piezoelectric device according to the present invention.

FIG. 1 is a plan view of the crystal oscillator of the present invention in a state where a cover is omitted, and FIG. 2 is a cross-sectional view.

The crystal oscillator 1 of the piezoelectric device according to the present invention comprises:
It is mainly composed of a container 2 having an insulating substrate 21, a quartz oscillator 3, a conductive adhesive member 4 and a metal lid 6.

The ceramic package 2, which is a container,
A rectangular single-plate ceramic substrate 21 and a ceramic substrate 2
1 and a seam ring 25 provided around the periphery. The seam ring 25 is used for the sealing conductor film 2.
4 and is fixed by brazing. And, as a whole, it has an opening on the front side as shown in FIG.
A substantially rectangular cavity portion 20 for accommodating the crystal resonator 3 is formed. Further, a pair of electrode pads 22 and 23 for electrically connecting to the crystal oscillator 3 are formed on one short side (the left side in FIG. 1) of the bottom surface of the cavity portion 20, that is, the upper surface of the substrate 21. I have. This electrode pad 2
The reference numerals 2 and 23 are formed separately in the width direction of the short side (the vertical direction in FIG. 1). Its shape is substantially rectangular.

The seam ring 25 is made of Fe—Ni,
It is made of a metal such as Fe-Ni-Co and is formed by brazing or the like on the sealing conductor film 24 formed around the substrate 21, thereby defining the thickness of the cavity portion 20. If this thickness is insufficient,
A ring-shaped substrate may be laminated around the substrate 21 and a seam ring 25 may be attached to the surface of the ring-shaped substrate.

On the bottom surface of the ceramic package 2, there are formed external terminal electrodes 26 electrically connected to the electrode pads 22 and 23 and joined to an external printed wiring board. The electrode pads 22 and 23 and the external terminal electrodes 26 are connected by via-hole conductors penetrating a part of the ceramic package 2. Electrode pad 22,
If the position of the external terminal electrode 26 does not correspond to the position of the external terminal electrode 26, a wiring conductor having a predetermined shape may be formed on the bottom surface of the cavity portion 22 so that the connection can be easily performed by the via-hole conductor. Further, the substrate 21 itself may be laminated in a two-layer structure, for example, and an internal wiring may be formed therebetween.
One end of the internal wiring is connected to an electrode pad via a via-hole conductor, and the other end of the internal wiring is connected to an external terminal electrode.

Further, as shown in FIG.
Band-shaped bumps 5 are formed on the surfaces of 2 and 23 near the center of the cavity 20. This strip-shaped bump 5
Are formed by baking a conductive metal paste, printing and curing a conductive resin paste and an insulating resin paste.

The above-described electrode pads 22 and 23, the sealing conductor film 24 and the bumps 5 are made of a metal such as molybdenum or tungsten. These conductors (electrode pads 22,
23, the conductor film 24, and the bump members 5) are formed by baking a conductive resin paste on the surface of the substrate 21 and then plating the surface with Ni and Au.

For example, when the bump 5 is formed by baking a conductive metal paste, a conductor serving as a base conductor for the electrode pads 22 and 23 is printed and formed with the above-mentioned metal paste, and after drying, the above-mentioned metal is formed on the surface. It is formed by printing using a paste in accordance with the shape of the bump 5 and then performing a baking process on both.

The thickness of these conductors (electrode pads 22, 23, conductor film 24, bump 5) is about 10 to 30 μm, and the height from the surface of substrate 21 to bump 5 is 20 to 6 μm.
The height is 0 μm. The width of the bump 5 is 10 to 2
0 μm.

The crystal unit 3 as a piezoelectric vibrating element includes, for example, a rectangular crystal substrate 30 cut (AT cut) according to a predetermined crystal azimuth angle, and an excitation formed on both main surfaces of the crystal substrate 30. Electrodes 31, 33 and a pair of excitation electrodes 3
Extraction electrodes 32 and 34 extend from the reference numerals 1 and 33 in the short side direction (left side in the figure) of the quartz substrate 30, respectively. For example, the extraction electrode 32 extending from the upper surface side excitation electrode 31 extends near the short side of the upper surface, and extends through one long side end surface (lower end surface in the drawing) near the short side. Has been extended to. Conversely, the extraction electrode 34 extending from the excitation electrode 33 on the lower surface extends near the short side of the lower surface, and via the other long side end surface (the upper end surface in the drawing) near the short side. It extends to the top side. That is, the extraction electrodes 32 and 34 are not formed on one short side end face of the quartz substrate 30, but are formed on the long side end face that is in contact with the one short side. The extraction electrodes 32 and 34 are formed at positions opposing each other on both main surfaces of the quartz substrate 30, and have a shape that can be electrically connected to the electrode pads 22 and 23 when arranged at a predetermined position. .

The excitation electrodes 31, 33 and the extraction electrodes 32, 34 are provided with a mask having a predetermined shape on the upper and lower surfaces of the quartz substrate 30, and Au, Ag, It is formed by vapor deposition of Cr or the like.

The above-described electrical connection and mechanical connection between the ceramic package 2 and the crystal unit 3 are performed by adding an Ag powder or the like to a resin such as a silicon-based, epoxy-based, or polyimide-based resin to form a conductive resin paste. Is achieved by the conductive adhesive member 4 which has been cured.

Specifically, the electrode pads 2 on the surface of the substrate 21
The above-mentioned conductive resin paste is supplied onto the electrode pads 22 and 23 by a dispenser or the like, and the crystal oscillator 3 is placed on the conical conductive resin paste raised on the electrode pads 22 and 23.
The crystal oscillator 3 is placed so that the extension electrode extended to the lower surface on one short side of the electrode abuts, and the conductive resin paste is cured.

Here, the conductive adhesive member 4 is provided between the extraction electrodes 32, 34 on the lower surface of the crystal unit 3 and the electrode pads 22, 23 on the surface of the substrate 21 of the ceramic package 2, for example, the height of the bump 5. As shown in FIG. 4, the quartz oscillator 3 is disposed on one short side end face of the quartz oscillator 3. Further, the conductive adhesive member 4 is not substantially attached to the surface of the crystal unit 3.

As a result, the pair of excitation electrodes 31 and 33 of the crystal unit 3 are electrically connected to the external terminal electrodes 26 on the outer surface of the ceramic package 2 via the electrode pads 22 and 23.

The metal lid 6 is made of substantially flat metal,
For example, Fe-Ni alloy (42 alloy) or Fe-Ni-C
o alloy (Kovar) or the like. Such a metal lid 6 has a housing area (cavity portion) 2 for the crystal unit 3.
0 is hermetically sealed with nitrogen gas or vacuum. Specifically, the metal lid 6 is placed on the seam ring 25 of the ceramic package 2 in a predetermined atmosphere, and the metal on the surface of the seam ring 25 and a part of the metal of the metal lid 6 are welded. A predetermined current is applied to perform seam welding. In order to perform this welding reliably, an Ag brazing layer or the like may be formed in advance on the joining surface side of the metal lid 6, and the brazing material melted by welding may be used as the metal lid 6.
A Ni plating layer may be formed on the surface side of the metal lid 6 so that the brazing material contributing to the joining does not decrease due to wraparound.

According to the structure described above, the electrode pad 22 and the electrode pad 22 are provided on the surface of the substrate 21 which is a part of the ceramic package 2.
23, the extraction electrode 3 of the crystal unit 3
2, 34 are electrically and mechanically joined via a conductive adhesive member 4 formed by curing a conductive resin paste.

More specifically, the conductive adhesive members 4 are disposed on the lower surface of the crystal unit 3 and on one short side end face, respectively. The conductive resin paste rises).
The substrate 21 of the ceramic package 2 (electrode pad 2)
2, 23) and the lower surface of the crystal unit 3 (lead electrodes 32, 34). Thereby, the bonding strength is improved, and when an external impact is applied due to dropping or the like, peeling is less likely to occur at this bonding portion, and the oscillation frequency does not greatly change or oscillation failure does not occur. . At the same time, the conductive adhesive member 4 adheres only to the lower surface and the end surface of the crystal unit 3, but does not substantially adhere to the front surface side. For this reason, since the conductive resin paste serving as the conductive adhesive member 4 does not easily spread from the extraction electrode 32 to the front-side excitation electrode 31, the oscillation characteristics of the crystal unit 3 and CI
(Crystal impedance) fluctuations can be effectively suppressed. Thus, the oscillation characteristics do not change.

The conductive resin paste which is to be spread on the lower excitation side 33 of the crystal unit 3 is applied to the electrode pad 22,
The conductive resin paste does not adhere to the lower surface-side excitation electrode 33, as in the surface-side excitation electrode 31 of the crystal resonator 3, because the band-shaped bump 5 regulates the position near the center of 23.

As a result, as a whole of the crystal unit 3, the conductive resin paste is applied to the excitation electrodes 31 and 3 of the crystal unit 3.
The area where the conductive resin paste is adhered to the crystal resonator 3 can be reduced without spreading to the side of the crystal resonator 3.

The above-described crystal oscillator is manufactured as follows.

First, the excitation electrodes 3 are provided on both main surfaces of the quartz substrate 30.
1 and 33, and a quartz oscillator 3 having extraction electrodes 32 and 34 extending to both main surfaces on one short side is prepared. Also,
At the same time, the bottom of the ceramic package 2, that is, the substrate 2
A ceramic package 2 having a pair of electrode pads 22 and 23 formed on the surface of the substrate 1, a sealing conductor film 24 and a seam ring 25 formed on the surface around the opening of the cavity 20, and a metal lid 6 is prepared.

Next, a conductive resin paste for forming the conductive adhesive member 4 is supplied and applied to the electrode pads 22 and 23 by using a dispenser or the like. At this time, the supplied conductive resin paste has a generally conical shape that is entirely raised.

Next, the quartz oscillator 3 is placed on the conductive resin paste supplied in a substantially conically raised shape.

Next, the conductive resin paste is cured, and the ceramic package 2 and the quartz oscillator 3 are fixedly joined. Specifically, it is cured by application of heat.

Thereafter, the seam ring 2 is placed in a predetermined atmosphere.
A metal lid 6 is placed on 5 and both are seam-welded.

In the conventional crystal oscillator, a conductive resin paste is applied on the electrode pads, the crystal oscillator is mounted, and then the conductive resin paste is applied from the front side of the crystal oscillator. The conductive resin paste is supplied again so as to conduct with the conductive resin paste.

On the other hand, in the present embodiment, the crystal resonator can be electrically connected and mechanically joined by one application of the conductive resin paste. The number can be reduced.

In the above embodiment, the quartz oscillator 3 is mechanically fixed to the electrode pads 22 and 23 only on one short side. That is, one short side of the crystal resonator 3 is a fixed connection end, and the other short side is a vibration free end.
Thus, the crystal resonator 3 can be said to be a cantilever fixed type.

As described above, in the cantilever fixed type, the substrate 21 and the excitation electrode 33 on the lower surface side of the crystal unit 3 can be set at a predetermined interval, for example, an interval of 10 to 30 μm. This is because when the conductive resin paste on one short side hardens to form the conductive adhesive member 4, the conductive resin paste shrinks and the stress acts. This stress acts to attract the vibration free end to the fixed connection end, and for example, the band-shaped bump 5 formed near the center of the electrode pads 22 and 23 becomes a fulcrum, and the other short side end It works to lift the vibration free end.

Thus, even if the substrate 21 located below the crystal unit 3 has a flat plate shape, there is no problem at all, and the substrate 21 has a two-layer structure because the stepped portions 55 and 56 are formed as in the prior art. No need to do. As a result, the height of the crystal unit can be reduced.

Also, in the present invention, the excitation electrodes 31, 3
3, extraction electrodes 32, 3 extending to both main surfaces on the short side
4 is routed through the end face on the long side of the crystal resonator 3, and no electrode is formed on the short side end face of the crystal resonator 3. This is because the adhesive force of the conductive resin paste is strong in the exposed portion of the quartz substrate when comparing the portion (electrode) where the metal is formed with the exposed portion of the quartz substrate. For this reason,
When the conductive adhesive member 4 is attached to the portion where the quartz crystal substrate 30 is exposed, the overall bonding strength is increased, and at the same time, the force for pulling up the above-mentioned free end is increased. This is advantageous for a fixed crystal resonator.

The inventor has studied the width W1 of the conductive adhesive member 4 in contact with the short side width of the crystal unit 3 and one of the extraction electrodes, for example, the short side end face of the 32 side.

When the width W1 of the conductive adhesive member 4 is relatively increased, when an external impact such as a drop is given,
Peeling is less likely to occur at the portion bonded by the conductive adhesive member.

However, since the portion to which the conductive resin paste is applied increases, the excitation electrodes 3 on the front and lower surfaces are formed.
There is a high possibility that the CI will spread to 1, 33, and the CI will worsen.

If the conductive resin paste can be prevented from spreading to the excitation electrodes 31 and 33 of the crystal unit 3, the fundamental wave will not be damped.

Conversely, if the bonding width W1 of the conductive bonding member 4 is too small, peeling tends to occur when an external impact is applied, and as a result, the oscillation frequency may fluctuate greatly.

For example, considering the dimensions of the actual crystal unit, the relationship between the width W of the conductive adhesive member 4 on the short side and the bonding width W1 of the crystal unit 3 is 0.22W ≦ W1 <0.5W. Become.

For example, in L, W, and W1 shown in FIG. 4, the end faces of the conductive adhesive member 4 and the quartz oscillator 3 are measured by using a piezoelectric vibrator having dimensions L = 3.5 mm and W = 1.8 mm. Was varied and the frequency variation was examined.

As a result, as shown in the characteristic diagram of FIG.
At 1 <400 μm, the frequency rapidly changed before and after the impact. However, W1 ≧ 400 μ
At m, the change in frequency can be reduced stably. From this, it was found that, when W1 / W, when W1 ≧ 0.22W, the change in frequency with respect to an external impact can be sufficiently suppressed.

Note that W1 <0.5 W is set so as to avoid a short circuit between the two conductive adhesive members 4 and 4 at one short side end face.

That is, when 0.22W ≦ W1 <0.5W, a piezoelectric vibrator having excellent impact resistance and excellent electric characteristics can be obtained.

For L ≦ 2.3W, in particular,
In the cantilever fixed type crystal unit 3, if the length L is extremely long with respect to the width W of the crystal unit 3, the stress at the time of hardening and shrinking of the conductive resin paste which becomes the conductive bonding member 4 is reduced. It is difficult to use and lift the free end side.

The inventor has determined that the width W and length L of the quartz oscillator 3
As a result of studying the relationship between L and 2.3 W, a cantilever fixing structure of the crystal resonator 3 can be achieved, the surface of the substrate 21 can be flattened, and the holding bump ( (Not shown), there is no contact with the surface of the substrate or the holding bumps.

FIGS. 6 and 7 are cross-sectional views showing another piezoelectric device of the present invention.

In the piezoelectric device (crystal oscillator) shown in FIG.
This is a structure for preventing short-circuit between the electrode pads 22 and 23 and the sealing conductor film 24 via the conductive adhesive member 4.

That is, as is apparent from FIG. 6, a first band-shaped bump 5a is provided near the center of the electrode pads 22 and 23, and a second band-shaped bump 5b is provided near the outside of the electrode pads 22 and 23. Is provided. This electrode pad 22,
23, two bumps 5a and 5b extending in the width direction on the short side of the crystal unit 3 are formed.

The two bumps 5a and 5b serve as dams, and the conductive resin paste supplied between them regulates the spread and prevents a short circuit with the sealing conductor film 24. ing. Incidentally, the structure of the two bumps 5a and 5b is as follows.
It is formed in the same structure and in the same process as the bump member shown in FIG.

FIG. 7 is a sectional view of a crystal oscillator showing another embodiment of the piezoelectric device of the present invention.

In this embodiment, FIGS. 1 to 6 show a quartz oscillator in which only the quartz oscillator 3 is housed in the container 2. On the other hand, FIG. 7 shows a crystal oscillator in which a cavity 8 for housing an oscillation circuit is formed on the lower surface side of the container.

The ring-shaped ceramic body 27 is integrated with the substrate 21 as a partition substrate so that another cavity 8 is formed on the lower surface side of the substrate 21. An external terminal electrode 2 is provided on the lower surface of the ring-shaped ceramic body.
6 are formed. Although the wiring pattern on the ceiling surface of the cavity 8 is omitted, the substrate 21 is laminated to provide the substrate 28 in order to cope with the complexity of the wiring pattern.

In the cavity 8, an IC for performing temperature compensation for the oscillation characteristics of the crystal unit 3 (operation for flattening the frequency-temperature characteristics of the crystal unit in a predetermined temperature range). A chip capacitor, a chip resistor (7 in the figure) necessary for an element, an IC element for amplifying the output of the crystal unit, and a control circuit for achieving such an operation.
Described).

That is, the present invention is applied not only to a crystal oscillator having only the crystal oscillator 1 but also to a crystal oscillator incorporating an oscillation circuit of a predetermined operation.

In the above-described embodiment, the description has been made using the quartz oscillator as the piezoelectric oscillation element. However, the present invention is not limited to the quartz oscillator. May be used as the piezoelectric single crystal vibrator.

[0072]

According to the present invention, there is provided a piezoelectric device in which a piezoelectric vibrating element is joined to an electrode pad having a band-shaped bump with a conductive adhesive member obtained by curing a conductive resin paste. The width W1 at which the short side of the element is bonded is 0.22W ≦ W1 <0.5W, L with respect to the width W in the short side direction and the length L in the long side direction of the piezoelectric vibrating element.
With a relationship of ≦ 2.3 W, a piezoelectric device excellent in impact resistance and excellent in electrical characteristics can be obtained.
The cantilevered piezoelectric vibrator can be stably maintained on the flat substrate, and the piezoelectric device can be reduced in height.

[Brief description of the drawings]

FIG. 1 is a top view of a quartz oscillator which is a piezoelectric device according to the present invention in a state where a lid is omitted.

FIG. 2 is a cross-sectional view of a crystal oscillator that is a piezoelectric device according to the present invention.

FIG. 3 is a perspective view showing a shape of a bump on an electrode pad used in the piezoelectric device of the present invention.

FIG. 4 is a top view showing the crystal unit in a state where it is bonded to an electrode pad of the piezoelectric device of the present invention.

FIG. 5 is a characteristic diagram showing a relationship between a junction width W1 and a frequency variation ΔF in a piezoelectric device.

FIG. 6 is a schematic sectional view showing another piezoelectric device of the present invention.

FIG. 7 is a schematic sectional view showing another piezoelectric device of the present invention.

FIG. 8 is a top view of a conventional piezoelectric device with a lid omitted.

9 is a cross-sectional view of the piezoelectric device shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Piezoelectric device (crystal oscillator) 2 ... Ceramic package 20 ... Cavity part 21 ... Substrate 22, 23 ... Electrode pad 24 ... Sealing conductor film 25 ... Seal ring 3 Crystal oscillator 30 Crystal substrate 31, 33 Excitation electrode 32, 34 Extraction electrode 4 Conductive adhesive member 5 Bump 5a, 5b Bump 6 ... Metallic lid 52 ... Ceramic package 53 ... Piezoelectric vibrating element 55 ... Step part for fixing 56 ... Step part on the tip side 57 ... Conductive adhesive member 58 ... Groove

Claims (1)

[Claims] 1. A piezoelectric vibrating element having an excitation electrode formed on both main surfaces of a rectangular piezoelectric substrate, and a pair of extraction electrodes connected to the excitation electrode on a lower surface near one short side of the piezoelectric substrate. A piezoelectric substrate formed by bonding an insulating substrate formed with a pair of electrode pads having bumps to each other through a conductive adhesive member so that the extraction electrode and the electrode pad are electrically connected to each other; When the width of the conductive adhesive member is W1, the width of the piezoelectric vibrating element in the short side direction is W, and the length of the long side direction is L, the relationship 0.22W ≦ W1 <0.5W L ≦ 2.3W A piezoelectric device characterized by being represented.